Adobe Extending Flash Professional CS5 - Manual (Page 332)

310 EXTENDING FLASH PROFESSIONAL
Instance object
Last updated 5/2/2011
instance.libraryItem
Availability
Flash MX 2004.
Usage
instance.libraryItem
Description
Property; a library item used to instantiate this instance. You can change this property only to another library item of
the same type (that is, you cannot set a
symbol instance to refer to a bitmap). See library object .
Example
The following example changes the selected symbol to refer to the first item in the library:
fl.getDocumentDOM().selection[0].libraryItem = fl.getDocumentDOM().library.items[0];